Doppler directed suture ligation device and method

ABSTRACT

A ligation device includes a cannula having first and second extendable members and a Doppler wand. The Doppler wand permits an anatomical vessel, such as a blood vessel, to be located in close proximity to the distal end of the cannula. The extendable members are extendable on two opposite sides of the vessel. A length of ligation material, such as suture material, extends through the first extendable member, and is attached to a detachable element mounted to the distalmost end of the extendable member. The second extendable member includes a snare. The first extendable member includes curved portions which, when the member is extended distally, extend the detachable element into position for the snare so that the snare can grab the loop. Once ensnared, the detachable element is released from the first extendable member, which pulls the ligation material around the vessel. The ligation device does not require prior visualization or dissection of the area around the vessel.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to ligation devices and methods, and moreparticularly to devices and methods for accurately locating and ligatingan anatomical vessel.

2. Brief Description of the Related Art

The Doppler effect is currently utilized in many fields. For example,Doppler stethoscopes and Doppler wands are currently utilized togenerate images of internal anatomical structures in patients,especially in mammalian patients. Continuous wave doppler sound signalsare used to identify blood vessels, but do not provide feedback as tothe distance of the vessel from the Doppler probe used. Pulsed waveDoppler has been used to identify blood vessels and, in conjunction withtwo dimensional (2D) imaging systems, identify the distance to a bloodvessel and blood flow characteristics. Ultrasound systems with Dopplerimaging are also currently used in medical fields, and typically producegray-scale two-dimensional images. The addition of Doppler processingallows for the evaluation of fluid flow velocities through fluidconduits within the patient, and the relative position of these vesselsto other anatomical structures.

Ligation devices have previously been proposed. These prior ligationdevices have typically been used in laparascopic procedures, and havetypically required that the anatomical feature of interest be dissectedor visualized prior to ligation of that feature.

SUMMARY OF THE INVENTION

According to a first exemplary embodiment, a ligation device comprises acannula having a proximal end, a distal end, and at least one lumenextending longitudinally from said proximal end to said distal end, afirst extendable member slidably received in said cannula lumen, saidfirst extendable member having a distal end and being movable in saidlumen from a retracted position in which said first extendable memberdistal end is proximal said cannula distal end, and an extended positionin which said first extendable member distal end is distal of saidcannula distal end, said first extendable member including a detachableelement at said first extendable member distal end, a second extendablemember slidably received in said cannula lumen, said second extendablemember having a distal end and being movable in said lumen from aretracted position in which said second extendable member distal end isproximal said cannula distal end, and an extended position in which saidsecond extendable member distal end is distal of said cannula distalend, said second extendable member including a snare at said secondextendable member distal end, and at least one of said first extendablemember and said second extendable member including curved portions whichextend laterally across said cannula when said at least one of saidfirst extendable member and said second extendable member is in saidextended position.

According to a second exemplary embodiment, a method of preparing ananatomical vessel for ligation comprises the steps of positioning acannula adjacent to said vessel, said cannula including a firstextendable member, a second extendable member, and a Doppler wand, and adistal end, transmitting ultrasound signals toward said vessel with saidDoppler wand, receiving ultrasound signals reflected by said vessel withsaid Doppler wand, extending said first extendable member on a firstside of said vessel, extending said second extendable member on a secondside of said vessel opposite said first side, and extending a length ofligation material between said first and second extendable members on aside of said vessel opposite said cannula distal end.

According to a third exemplary embodiment, a device useful for guiding alength of ligation material around an anatomical feature comprises acannula including a hollow interior, a distal end, and a fenestration inthe cannula proximal of the distal end, a hollow arm positioned in thecannula at the fenestration, the hollow arm including a rotatable pivotby which the arm is mounted to the cannula, the arm being rotatable froma retracted orientation with the arm positioned inside the cannula and adeployed orientation with a portion of the arm rotated about the pivotand through the fenestration, at least one wire connected to the arm andextending proximally, and wherein when the at least one wire is pulledproximally, the arm is rotated about the pivot into the deployedorientation.

Still other objects, features, and attendant advantages of the presentinvention will become apparent to those skilled in the art from areading of the following detailed description of embodiments constructedin accordance therewith, taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention of the present application will now be described in moredetail with reference to preferred embodiments of the apparatus andmethod, given only by way of example, and with reference to theaccompanying drawings, in which:

FIG. 1 illustrates a top, distal, side perspective view of an exemplaryembodiment of a doppler directed ligation device in accordance with thepresent invention;

FIG. 2 illustrates the ligation device of FIG. 1, with portions removed;

FIG. 3 illustrates a cross sectional view taken along line 3—3 in FIG.1;

FIGS. 4-6 illustrate a snare in accordance with the present invention;

FIG. 7 illustrates an enlarged perspective view of the distal end of theembodiment illustrated in FIG. 1;

FIGS. 8-10 illustrate a loop in accordance with the present invention;

FIGS. 11-13 illustrate portions of the device illustrated in FIG. 1;

FIG. 14 illustrates a portion of the device illustrated in FIG. 1;

FIG. 15 illustrates an enlarged view of the portions illustrated in FIG.14;

FIG. 16 illustrates a cross sectional view taken along line 16—16 inFIG. 1;

FIGS. 17-19 illustrate enlarged plan views of further embodiments inaccordance with the present invention;

FIGS. 20-24 illustrate the device of FIG. 1 used in accordance with anexemplary embodiment of a method of ligating an anatomical feature in apatient;

FIG. 25 illustrates portions of yet another embodiment of the presentinvention;

FIGS. 26A and 26B illustrate portions of further embodiments of thepresent invention; and

FIGS. 27-30 illustrate several views of yet another embodiment inaccordance with the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawing figures, like reference numerals designateidentical or corresponding elements throughout the several figures.

FIG. 1 illustrates a top, distal end, side perspective view of anexemplary embodiment of a doppler directed ligation device 100 inaccordance with the present invention. FIG. 1 illustrates device 100deployed to enable a practitioner to ligate a fluid vessel 10. Whilevessel 10 is preferably a uterine artery, other vessels, such as otherarteries, veins, fallopian tubes, urinary ducts such as the ureter, andother fluid vessels can be ligated with device 100 within the spirit andscope of the present invention, as will be readily appreciated by one ofordinary skill in the art. Different from ligation devices which havepreviously been proposed, as well as their uses, ligation devices andmethods in accordance with the present invention do not requiredissection of the vessel 10, and does not require actual visualizationof the vessel, prior to ligation. The capability enabled by the presentinvention of advancing a ligation device through tissue beds and/ortissue planes without the need for dissection can provide benefits asdescribed elsewhere herein and as will be readily appreciated by one ofordinary skill in the art.

Ligation device 100 includes a proximal handle 102 and a cannula 104extending distally from the handle. Handle 102 includes a hollow housing103 sized and shaped to fit comfortably in the hand of a practitioner. Aproximal thumb ring 106 is fixed to the housing 103 opposite cannula104. A pair of top slots 108, 110 are formed in the top surface 107 ofthe housing 103, and a pair of side slots 109, 111, are formed in thesidewalls 113, 115. A first actuation ring 112 and a second actuationring 114 are slidably mounted in housing 103, through the opposite sideslots 109, 111 (see also FIG. 2) of the housing. Upstanding tabs 116,118, extend from the interior of housing 103, through slots 108, 110,respectively, to outside the housing. The slots 109, 111 limit the rangeof motion of the rings 112, 114, and the slots 108, 110 function tolimit the range of motion of the tabs 116, 118 along longitudinaldirection X.

Cannula 104 is fixedly mounted to the distal end of handle 102. Cannula104 includes a plurality of lumenae extending longitudinally through thecannula, which are best illustrated in FIG. 3. Ligation device 100includes a first extendable element 120 which is longitudinally slidablethrough cannula 104 between a retracted position (see, e.g., FIG. 20) inwhich the first extendable element is housed entirely inside thecannula, and an extended position (see, e.g., FIG. 21) in which thefirst extendable element extends distally beyond the distal end 150 ofthe cannula. Ligation device also includes a second extendable element122 which, similar to first extendable element 120, is longitudinallyslidable through cannula 104 between retracted and extended positions.First and second extendable elements 120, 122 are connected to first andsecond actuation rings 112, 114, respectively, at the proximal ends ofthe extendable elements, so that the rings can be used to longitudinallyadvance and retract the extendable elements in cannula 104.

The first and second extendable elements 120, 122 are positionedlaterally opposite each other in cannula 104, as best illustrated inFIG. 3, so that when they are in their extended positions they can bepositioned on opposite sides of an anatomical vessel, such as vessel 10.Furthermore, first and second extendable elements 120, 122 are sized sothat they both are extendable farther than a distance X_(ref) from thedistal end 150, described in greater detail below, so that a vessel 10can be bracketed by the extendable elements when the vessel is withinX_(ref) from the distal end of cannula 104.

First extendable element 120 carries a detachable element at its distalend. In the embodiment illustrated in FIG. 1, the detachable element isa loop 124. Loop 124 is attached, either directly or indirectly as willbe described in greater detail below, to a length of threadlikematerial, such as suture material, which may optionally further includea leader, which extends proximally through cannula 104. Secondextendable element 122 carries a snare element which is sized andconfigured to grab, ensnare, or otherwise become secured with thedetachable element of the first extendable element 120 when the firstand second extendable elements are in their extended positions (seeFIGS. 1 and 23). n the embodiment illustrated in FIG. 1, the snareelement is a hook 126. Loop 124 and snare 126 will be described ingreater detail below with reference to FIGS. 4-13.

Ligation device 100 further includes a doppler ultrasound device or wand140 mounted in the ligation device. In accordance with the presentinvention, the Doppler ultrasound device can be removably mounted in theligation device, or the components of a doppler ultrasound device can beintegrated into the ligation device, e.g. into cannula 104, so as not tobe removable. Thus, when the Doppler ultrasound device is removablymounted in ligation device 100, the Doppler ultrasound device can beremoved at the termination of a use, removed from the remainder of theligation device, and the Doppler ultrasound device sterilized andreused. Alternatively, when the Doppler ultrasound device's componentsare integrated into the ligation device 100, the entire ligation devicecan be disposed of at the conclusion of a use.

Cannula 104 includes a third center lumen 138 (see FIGS. 3 and 7) intowhich a removable doppler wand 140 is removably inserted. According tocertain embodiments of the present invention, a distal end 152 of thedoppler wand is proximal of the distal end 150 of the cannula. Accordingto other embodiments of the present invention, the distal end 152 of thedoppler wand 140 is positioned at the distal end 150 of the cannula.According to other embodiments of the present invention, the distal end152 of the doppler wand 140 is positioned distal of the distal end 150of the cannula. Preferably, housing 103 includes portions which receivethe proximal portions of doppler wand 140, so that the doppler wand canbe removed and reused after ligation device 100 has been used. Forexample and not by way of limitation, housing 103 can include portionswhich are hinged together and secured with a snap, lock, or the like, sothat the housing can be opened up, a doppler wand 140 inserted intoligation device 100, and the housing portions closed and locked tosecure the doppler wand in the ligation device.

Doppler ultrasound wands suitable for use in the present invention arepresently commercially available. For example, Koven model ES 100XMiniDop VRP-8 probe (St. Louis, Mo.) is a continuous wave doppler wandsuitable for use as doppler wand 140, and DWL/Neuro Scan MedicalSystems' Multi-Dop B+ system with their 8 MHz handheld probe (Sterling,Va.) is a continuous and pulsed wave doppler wand suitable for use aswand 140. Commercially available doppler stethoscopes or wands have anultrasound dispersion pattern which is generally conical, i.e., the wand“looks” out along a cone-shaped portion of a plane originating at theend of the wand. Thus, vessels with fluid flow in them, such as a bloodvessel, which lie anywhere in this conical plane and within theeffective range of the wand would be picked up by the wand. Dopplerwands presently available are attached to a signal processing anddisplay unit 156, which processes the electrical signals generated bywand 140 to generate displays and/or other data derived from theelectrical signals for additional uses. Alternatively, the Dopplersystem can be gated to identify blood vessels within a predetermineddistance range, e.g. from between 0 to 5 cm, more preferably between 0.5and 3 cm.

Unit 156 includes a display 158 which indicates the distance from thedistal tip 152 the source of reflected ultrasound waves is located,e.g., vessel 10. This information is typically calculated utilizing apredetermined function, because the distance is a function of the timeit takes for the ultrasound waves to travel to and from the wand. Unit156 preferably also includes a display or meter 161 of the magnitude ofthe reflected ultrasound waves' doppler shift, which is the indicationof the velocity of the fluid flowing through vessel 10. Unit 156 alsopreferably includes a sound source 163 which gives an audible indicationof the doppler shift, which can be louder when the Doppler shift isgreater or the vessel is optimally positioned.

In the ligation device of the present invention, however, such a wideconical “field of view” typically returned by many commerciallyavailable doppler wands is not preferable, because the practitioner isconcerned with locating the vessel between the extendable elements inorder to ligate the vessel. Were the present invention to utilize such“wide-view” Doppler wands without narrowing or otherwise affecting theirfield of view, vessels which are not directly distal of ligation device100 would be picked up by the device, and would return doppler shiftdata for vessels not of interest in the use of the ligation device.Ligation device 100, and specifically cannula 104, is therefore sized sothat the distalmost end 152 of doppler wand 140 is spaced proximallyfrom the distal end 150 of the cannula, for use with “wide-view” wandsto collimate the signal. Some commercially available doppler wands, suchas the aforementioned DWL probe, however, produce a sufficientlycollimated signal so that further collimation is not necessary.

When utilizing a Doppler probe which does not produce a sufficientlycollimated signal, lumen 138 is preferably coated, formed of a material,or is otherwise provided with a sleeve of a material on the interiorsurface of which collimates the sound waves emanating from doppler wand140. By way of example and not of limitation, lumen 138 can be coated orformed of polycarbonate, although other materials are also usable withinthe spirit and scope of the present invention.

The result of spacing distal end 152 proximally of distal end 150, andoptionally further providing a material and/or sleeve which acousticallycollimates the ultrasound waves from wand 140, is that ligation device100 is substantially unidirectional in its doppler field of view in adirection parallel with, and preferably between, first and secondextendable elements 120, 122, and longitudinally distal of distal end150. Stated differently, ligation device 100 is capable of receivingreflected ultrasound waves, originating from doppler wand 140, reflectedback from anatomical features directly distal of distal end 150. Thus,because distal end 152 is a fixed and known distance from distal end150, and X_(ref) is known, a maximum distance X_(max) is predeterminedby the structures of ligation device 100 within which a vessel 10 mustbe in order for the ligation device to be capable of ligating it. Statedsomewhat differently, once it is determined that a vessel is within apredetermined distance of distal end 152, which is indicated by the timelag of the reflected ultrasound waves, ligation device 100 can be usedto ligate that vessel.

According to another embodiment in accordance with the presentinvention, a doppler wand can be chosen which has a “field of view”which is narrow enough that, when used in the combination of theligating device 100, additional collimation structures are notnecessary. For example, selection of a probe is based on its field ofview and its operating frequency, and should also be based on thedistance between the target artery and the Doppler probe so that theprobe's depth of view is larger than this distance yet not so long as toinclude other blood vessels. By way of example and not of limitation, aDWL Doppler probe as described above can be used as wand 140 withoutrequiring either a collimating sleeve and without spacing the distal endproximal of distal end 150. In general, Doppler wands suitable for useas Doppler wand 140 are selected with small enough diameter to beinsertable in cannula 104, preferably operate at a frequency which issufficiently sensitive to blood flow to monitor uterine artery bloodflow, have a relatively narrow field of view and limited depth of viewso as not to generate a signal from other blood vessels, and can bebased on either pulsed or continuous wave Doppler signals.

FIG. 3 illustrates a cross-section view of ligation device 100, as seenalong line 3—3 in FIG. 1, and FIG. 7 illustrates an enlarged distal endperspective view of ligation device 100. Cannula 104 preferably has anoval cross sectional profile, so that the cannula can be relativelycompact while still meeting the requirement that doppler wand 140 belaterally between extendable elements 120, 122. As illustrated in FIG.3, cannula 104 includes a first lumen 130 which longitudinally andslidingly receives first extendable element 120. Preferably, element 120itself includes a lumen 142 through which a tubular suture and loopadvancing element 134 is longitudinally slidable. Element 120 furtheroptionally is provided with a slot or cutout 170 at its distal end inthe wall of the element 120 adjacent to or facing element 122, to assistin guiding or positioning loop advancing element 134 in a desireddirection and to assist in preventing rotation of the loop advancingelement relative to the element 120.

Suture advancing element 134 at least in part is formed of asuperelastic material, less preferably a shape-memory alloy (SMA)material, also less preferably (surgical) stainless steel. NiTi(nitinol) is preferred, although other superelastic, SMA, andbiocompatible materials are within the scope of the present invention.Forming at least portions of suture advancing element 134 of NiTi allowsthe suture advancing element to be preformed with a curved distal end,so that the suture advancing element can be easily retracted into firstextendable element 120, yet the distal end will accurately position loop124 to be snared by extendable element 122 when the suture advancingelement is advanced out of the first extendable element.

Suture/loop advancing element 134 preferably is a hollow tube andincludes structure at the distal end of the element which holds loop124, the loop in turn being attached to a length of suture material 154(see also FIG. 24). A more detailed description of the structures at thedistal ends of extendable elements 120, 122 is presented below withreference to FIGS. 4-13.

Cannula 104 includes a second lumen 132 in which second extendableelement 122 is longitudinally slidably received. Second extendableelement 122 preferably includes a lumen 144 which longitudinallyslidably receives an extendible hooking or snaring element 136. Cannula104 also includes a third lumen 138 which removably receives dopplerwand 140, so that the doppler wand can be used with the other structuresof ligation device 100 and then disassembled, as discussed above.Optionally, the ligation device 100, including the third lumen 138, cannon-removably house the functional components of a Doppler wand, so thatthe entire ligation device can be conveniently disposed of.

As illustrated in FIG. 7, the first and second extendable elements 120,122 can optionally further be provided with closed, preferably conicallyor frustoconically shaped tips 121, 123, respectively. The closed tips121, 123 permit the extendable elements 120, 122 to be more easilyadvanced through tissue beds and planes. When provided with the closedtips 121, 123, the extendable elements 120, 122 further includelaterally inwardly facing openings 125, 127 So that the elements 134,136 can pass out of the elements 120, 122, as described elsewhereherein. Further optionally, the distal interiors of one or both of theclosed tips can be provided with cam surfaces (not illustrated) toassist in guiding the detachable elements and/or the snaring elements.

FIGS. 4-6 illustrate several views of snaring element 136 including hookor snare 126. As detailed in FIG. 5, snare 126 includes an enlarged head160 having an angled slot 162. A hook portion 164 is formed distally ofslot 162. Slot 162 has a width W₁ and extends into head 160 at an angleα. A shank 166 is attached at the proximal end of head 160, and ispreferably formed integrally therewith from a single piece of material.Alternatively, shank 166 and head 160 can be press-fit, welded,adhesively bonded, or otherwise formed separately and thereafter joinedtogether as will be readily apparent to one of ordinary skill in theart. Width W₁ is selected to be greater than the width W₂ of loop 124(see FIG. 9), so that the loop can be deflected into slot 162 by hookportion 164 and slide into the slot and be grabbed by snare 126.Optionally, the proximal portions of head 160 adjacent to the opening toslot 162 can be widened, as indicated in phantom lines in FIG. 5, whichcan facilitate loop 124 being deflected by hook portion 164 into slot162.

FIGS. 8-13 illustrate distal end portions of suture/loop advancingelement 134. As illustrated in FIGS. 8-10, loop 124 is preferablyroughly oval in shape, and is temporarily mounted to the distal end of atubular curved element 172 (see also FIG. 13). A length of suturematerial 154 or the like is tied, glued, crimped, or otherwise securedto loop 124, and extends proximally through tube 172. As illustrated inFIGS. 11-13, suture/loop advancing element 134 includes a straightportion 174 and a curved portion 172, both of which are hollow tubes.Straight portion 174 and curved portion 172 are joined together at ajoint 180. Optionally, element 134 can be a monolithic element withoutsuch a joint 180, and a straight portion 174 and a curved portion 172can be formed therein, as will be readily appreciated by one of ordinaryskill in the art.

At least curved portion 172 of element 134 is preferably formed of asuperelastic material. Alternatively, portion 172 can be formed of a SMAmaterial. While the characteristics and use of superelastic materialsare readily appreciated by one of ordinary skill in the art, a briefdescription as applied to curved portion 172 will aid in anunderstanding of the present invention. Portion 172 is preferably formedof an superelastic material, e.g., NiTi (nitinol). Portion 172 is givena curvature or bent configuration which, upon heating of the curvedportion above a certain temperature for the superelastic material, is‘remembered’ by the curved portion. In the embodiment illustrated inFIGS. 11-13 curved portion 172 is formed into an arc having a radius Rand the distal end 176 being at an angle β from a line perpendicular tostraight portion 174. Distal end 176, when curved portion 172 is in itscurved configuration, is a lateral distance Y from the straight portion174.

The length of curved portion 172 and the shape, as well as the distanceY, are selected so that when curved portion 172 is in its curvedconfiguration, loop 124 is positioned directed distally of secondextendable element 122. In this location, snare 126 can be extended andcan hook loop 124, to be pulled from suture/loop advancing element 134.The angular orientation of the lateral direction in which curved portion172 extends when in its curved configuration can be preset so that loop124 registers or lines up with snare 126, and slot 170 assists inmaintaining this orientation. This present angular orientation can bedetermined, by way of example and not of limitation, by heating curvedportion 172 above its transition temperature and rotating element 134until loop 124 is directly distal of snare 126, prior to using device100.

Curved portion 172 and straight portion 174 can both be formed of thesame (superelastic) material. Alternatively, only portion 172 is formedof an superelastic material, and straight portion 174 can be formed ofanother material, e.g., stainless steel, and the two portions 172, 174can be joined together at joint 180, as by welding, crimping, swaging,adhesive bonding, or the like. The distalmost end of portion 172includes a slot 178 in which loop 124 is temporarily held. Slot 178 hasa width W₃ and a depth D selected so that loop 124 can be receivedtherein by a press fit, or loosely received and crimped therein. Loop124 is not permanently held in slot 178, however, and is mounted in theslot so that the loop can be pulled out of the slot by a preselectedforce transmitted by snare 126 after the loop has been hooked by thesnare (see, e.g., FIG. 3).

FIG. 14 illustrates internal portions of ligation device 100. First andsecond extendable elements 120, 122 are mounted in a block 190 to whichrings 112, 114 are also fixedly secured. Thus, as described above,proximal and distal longitudinal movement of rings 112, 114 moves firstand second extendable elements 120, 122. Block 190 includes a pair ofslots 192, 194 formed in a top surface thereof in which tabs or pins116, 118 are slidably received, respectively. Thus, the slots 192, 194constrain the tabs 116, 118 laterally, while permitting them to movelongitudinally over a range limited by the length of the slots.

FIG. 15 illustrates a top plan view of distal portions of the viewillustrated in FIG. 14. As can be seen in FIG. 15, the block 190includes slots 192, 194, described above. According to one embodiment ofthe present invention, block 190 includes first and second lateralportions 196, 198, which are cylindrical in shape, in which the firstand second extendable elements 120, 122 are mounted, respectively.According to one embodiment of the present invention, lateral portions196, 198 can be fixedly joined together as a with a web 200, so thatmovement of one of the rings 112, 114 moves both lateral portions.According to yet another embodiment of the present invention, lateralportions 196 and 198 are not joined together, and are thereforeseparately and individually longitudinally moveable in housing 103.

Also visible in FIG. 15 are mounting blocks 202 and 204 positioned inblock 190. Mounting block 202 fixedly receives the proximal portion ofextendable element 134 and lower portions of tab 116, and mounting block204 fixedly receives the proximal portion of extendable element 136 andtab 118. Block 202 thus joins together extendable element 134 with tab116, and block 204 thus joins together extendable element 136 with tab118. Additionally, blocks 202 and 204 constrain tabs 116 and 118 frombeing pulled up and out from block 190, as their lateral extents arelarger than slots 192, 194, respectively.

FIG. 16 illustrates a cross-sectional view of proximal portions ofligation device 100. As can be seen in FIG. 16, the housing 103 includesan interior chamber or cavity 210 which slidingly receives block 190 andits components. Block 190 includes an interior chamber or cavity 208which slidingly receives blocks 202 and 204 (block 204 is not visible inthe view of FIG. 16), and a proximal opening 206 which communicatesinterior chamber 208 with interior chamber 210. Proximal opening 206also permits blocks 202, 204 to extend into interior chamber 210. FIG.16 also illustrates suture 154 extending through loop advancing element134, block 202, interior chamber 208, interior chamber 210, and exitinghousing 103 through one of slots 108-111.

FIGS. 17-19 illustrate further embodiments in accordance with thepresent invention. In the embodiment illustrated in FIG. 17, both a loopadvancing element 220 and a snare advancing element 222 are formed of asuperelastic, SMA, or stainless steel material, and curve to meet eachother. In the embodiment illustrated in FIG. 18, snare advancing element136 is formed of a superelastic, SMA, or stainless steel material, andloop advancing element 134 is advanced directly longitudinally distallyto be snared by the snare 126. In the embodiment illustrated in FIG. 19,a first curved tube 230 of a superelastic, SMA, or stainless steelmaterial, and a second curved tube 232 of a superelastic, SMA, orstainless steel material, meet in a manner similar to the embodimentillustrated in FIG. 17. The distal ends of tubes 230, 232 mate in asomewhat different fashion, one of the tubes 230, 232 bearing a snarewhich is a receptacle 234 having a bore 238 having an internal diameterlarger than the, external diameter of the other of tubes 230, 232. Thus,when the tubes 230, 232 meet, the distal ends engage. A pushrod or wire236, to which suture 154 is attached, is positioned in one of the lumensof tubes 230, 232, and is pushed distally down that tube, throughreceptacle 234, and proximally up the other of tubes 230, 232. Thus, asuture can be advanced around a blood vessel of interest in a mannersimilar to the embodiments described above.

FIGS. 20-24 illustrate several steps of an exemplary method inaccordance with the present invention. While FIGS. 20-24 illustrate, andthe following description makes reference to, ligation device 100,methods in accordance with the present invention are not limited to useof ligation device 100, and other apparatus can be utilized inpracticing the present methods without departing from the spirit andscope of the present invention.

FIG. 20 illustrates the distal end of ligation device 100 after havingbeen positioned proximate a vessel of interest in a patient, e.g., auterine artery 10. Distal end 150 of cannula 104 is initially positionedaway from vessel 10. Distal end 150 is accurately positioned withinX_(max) of the vessel by pointing cannula 104 in several directionsaround where the practitioner believes the vessel is located, monitoringthe output of unit 156 for distance and velocity data to determine therelative location of the vessel relative to distal end 150, andrepositioning the distal end until the distal end is a distance X fromvessel 10 less than X_(max). As described above, reflected ultrasoundwaves 182, which are preferably collimated, are received by doppler wand140 (or the functional components thereof, integrated into ligationdevice 100) and are processed by unit 156 to indicate the relativelocation of vessel 10. For example, Doppler sound is utilized to findthe vessel location, and thereafter pulsed wave Doppler is utilized toidentify a more precise location and the distance to the artery 10.

Once the practitioner has established that vessel 10 is directly distalof the distal end 150 of cannula 104, first and second actuation rings112, 114 are moved distally to move first and second extendable members120, 122 distally, as illustrated in FIG. 21. Then, as illustrated inFIGS. 22 and 23, suture/loop advancing element 134 and snaring element136 are both distally advanced by pushing tabs 116, 118 distally; theadvancement of elements 134 and 136 can be serial, simultaneous, orcombinations thereof. Because suture/loop advancing element 134 isinside a (preferably mammalian) patient while it is advanced, thesuture/loop advancing element is heated up in situ above its SMAtransition temperature, and transforms from its straight configurationto its ‘remembered’ or curved configuration. Thus, advancement ofadvancing element 134 out of member 120 is accompanied by element 134assuming, or having already assumed, its curved configuration. Element134 and loop 124 are therefore advanced in a lateral direction andtoward element 136 and snare 126.

While the loop 124 is positioned directly distal of snare 126, snaringelement 136 is moved distally to advance snare 126 distally. Snare 126,and more particularly head 160, enters loop 124, and is pushed throughthe loop. Snare 126 is then retracted proximally so that hook portion164 deflects loop 124 into slot 162, thus causing the loop to be grabbedby the snare. In this respect, a widened mouth to slot 162, as suggestedby phantom line 168, can facilitate capture of loop 124.

With loop 124 ensnared by snare 126, snaring element 136 is retractedproximally, which pulls on the loop in a proximal direction. As thematerials out of which portions 172, 174 are formed are relatively rigid(superelastic, SMA, and stainless steel being preferable), the forceapplied by snaring element 136 to loop 124 will cause the joint betweenloop 124 and slot 178 to break or otherwise release the loop fromelement 134. As will be readily appreciated by one of ordinary skill inthe art, the joint between loop 124 and slot 178 is designed as abreakaway element, with the minimum force needed to break the jointselected so that the loop will not prematurely break free of curvedportion 172, yet not so high that a practitioner will not readily beable to generate the required force by pulling proximally on tab 118.Once loop 124 has been broken free of slot 178, snaring element 136 andsecond extendable element 122 are further pulled proximally so that theloop is pulled into cannula 104. As described above, suture material 154extends through curved portion 172 and is secured to loop 124, and istherefore pulled along with the loop.

Thus, suture material 154 is advanced distally past vessel 10 by distalextension of first extendable element 120 and suture/loop advancingelement 134, is advanced laterally behind the vessel by curved portion172 having assumed its curved superelastic configuration, and isadvanced proximally by proximal retraction of loop 124 after having beengrabbed by snare 126. With the loop of suture material passing aroundvessel 10, ligation device 100 can be pulled proximally, leaving theloop of suture material around vessel 10, as illustrated in FIG. 24. Atthis point, the practitioner can make whatever form of ligation shechooses, as the loop of suture material has been accurately passedaround the vessel 10 of interest.

FIG. 25 illustrates yet another embodiment in accordance with thepresent invention. The embodiment illustrated in FIG. 25 is similar tothat illustrated in FIG. 3, but differs in the cross-sectional profileof the device 250. Instead of the oval cross-sectional profileillustrated in FIG. 3, device 250 includes the coplanar lumenae 130,132, 138 defined in three adjacent and joined tubes 252, 254, 256.

FIGS. 26A and 26B illustrate alternative embodiments useful for passingand ensnaring suture material, such as suture material 154, as devices260, 280. The device 260 includes a detachable arrowhead shaped element262 at the end of suture/loop advancing element 134 to which a length ofligation material is attached as discussed elsewhere herein. A inwardlylaterally directed opening 264 is formed in the end of snaring element136. The opening 264 has an inner dimension selected so that thearrowhead element 262 will pass into the passageway 264 when properlyaligned therewith. Once the arrowhead element 262 has passed into theopening 264, the snaring element 136 can be retracted in a mannersimilar to that described above, causing the arrowhead element 262 to becaught and ensnared in the interior of the snaring element, andthereafter detached from the element 134. The snaring element 136 canoptionally further be provided with a second opening 266 (indicated inphantom) opposite the first opening 264, so that the arrowhead element262 can be passed entirely through the snaring element to be ensnared.

Further optionally, the element 134 can be electrically insulated on itsexterior surface proximal of the detachable arrowhead 262, as indicatedby dithering 268, and element 136 can similarly be electricallyinsulated on its exterior surface proximal of a preselected point 270,as indicated by dithering 272. When provided with this electricalinsulation, the arrowhead 262 and the portion 274 of the element 136distal of the point 270 can be electrically connected to opposite polesof a bipolar RF electrical energy source (not illustrated) and thearrowhead can be used as an RF cutter to easily push through tissue bedsand tissue planes which lie between it and the opening 264. For example,proximal portions of the elements 134, 136 can be electrically connectedto an RF energy source to permit the arrowhead 262 to act as an RFcutter, as will be readily appreciated by one of ordinary skill in theart.

FIG. 26B illustrates aspects of yet another alternative embodiment inaccordance with the present invention, device 280. Device 280 is similarin some respects to device 260. Device 280 includes a detachable ball282 mounted at the distal end of element 134. The ball 282, whenadvanced into opening 284 or through to opening 286, is ensnared by thesnaring element 136 in a manner similar to that described elsewhereherein.

FIGS. 27-30 illustrate several views of yet another embodiment inaccordance with the present invention. Turning to FIG. 27, an extendibleelement 300 is illustrated with portions removed to aid in a betterunderstanding of the extendible element. Element 300 can be used insteadof any of the above-described extendible elements, e.g., elements 120,122.

Element 300 includes a longitudinally extending cannula or tube 302having a hollow interior 303. A stationary guide tube 304 is mounted inthe cannula 302 and has a distal end 305 which is positioned proximallyof the distal end of the tube 302. The guide tube 304 is provided toguide a pushrod or the like carrying a length of suture material (notillustrated) toward the distal end of the tube 302. A pair of wireguides 306, 308 are mounted to the top and bottom of the of the guidetube 304 adjacent to its distal end, and extend distally out of thedistal end 305 of the guide tube. The guides 306, 308 are preferablyformed of a flexible material and are flat in cross-section so that whena suture-bearing pushrod or the like is advanced out the distal end ofthe guide tube 304, the pushrod is caused to follow a path between thewire guides 306, 308.

The distal ends of the wire guides 306, 308 are positioned in a hollowarm 310, and are preferably not secured to the hollow arm. The arm 310is attached to the cannula 302 at a pivot 326. The cannula 302 includesa window, cutout, or fenestration 320 adjacent to the arm 310, and issized and positioned so that the arm 310 can rotate between a deployedorientation, illustrated in FIGS. 27 and 28, and a retractedorientation, illustrated in FIG. 29, without hitting or otherwiseinterfering with the cannula. The arm 310 can have any of a number ofcross-sectional configurations, including the somewhat rectilinear shapeillustrated in the embodiment of FIGS. 27-30.

The element 300 also includes two pulling elements with which theorientation of the arm 310 can be controlled. In the embodimentillustrated in FIGS. 27-30, the pulling elements include a pair of upperpullwires 312, 314, which extend from within proximal portions of thecannula 302 to an attachment region 350 on the arm 310. The pullingelements also include a pair of lower pullwires 316, 318, which extendfrom within proximal portions of the cannula 302 to an attachment region352 on the arm 310. As the attachment regions 350, 352 are on oppositesides of the arm 310 (top, bottom, respectively), pulling on thepullwire pairs will result in moving the arm to either the deployedorientation or the retracted orientation. More specifically, pulling onthe upper pullwire pair 312, 314 causes the arm to rotate clockwise (inthe view illustrated in FIG. 27), So that the arm extends generallytransverse to the cannula 302. Conversely, pulling on the lower pullwirepair 316, 318 causes the arm to rotate counterclockwise (again, in theview illustrated in FIG. 27), so that the arm is within the cannula'shollow interior and extends longitudinally.

The element 300 preferably includes one or more structures whichfacilitates operation of the upper pullwires 312, 314. A port 328 ispreferably formed through the cannula wall somewhat proximally of thefenestration 320, and the upper pullwire pair extends through this upperport. Additionally, a groove or trough 330 is optionally formed in theouter surface of the cannula between the port 328 and the fenestration320. The trough 330 is sized to be deep enough to receive the upperpullwire pair so that when the arm 310 is in the retracted orientation,the pullwires are positioned in the trough and do not extend much or atall beyond the outer diameter of the cannula. FIGS. 29 and 30 illustratethe arm 310 in the retracted orientation, and the upper pullwires 312,314 positioned in the trough 330. Thus, the proximal lip of the port 328acts as a bearing surface for the upper pullwires 312, 314 as they movelongitudinally and the arm 310 pivots about pivot 326.

The element 300 preferably includes structure which permits the lowerpullwires to rotate the arm 310. In the embodiment illustrated in FIGS.27-30, a yoke 322 is positioned in the cannula 302 with the lowerpullwires 316, 318 extending around the yoke 322. FIGS. 28 and 30 betterillustrate details of the yoke 322. The yoke 322 is mounted in thecannula 302 distally of the pivot point 326 and preferably below thepivot point. As will be readily appreciated from FIGS. 27-30, pullingproximally on pullwires 316, 318 results in the arm 310 rotating downinto the cannula 302 through the fenestration 320, and into theretracted orientation. For ease of positioning the yoke 322 into theelement 300, the cannula 302 may optionally include an opening 332 intowhich the yoke 322 partially extends. The opening 332 can be eliminated.

Also illustrated in FIG. 27 is a stationary tube 324 which extends alongthe bottom of the cannula 302. The stationary tube 324 is provided sothat a practitioner can advance other tools through the element 300without interfering with the operation of the arm 310. By way of exampleand not of limitation, tools such as an anesthesia needle or the likecan be advanced distally through the tube 324 from its proximal end (notillustrated) to its distal end 336 (see FIG. 28). The arm 310 alsopreferably includes a cutout portion 340 on the upper surface of the arm(when in the retracted position; on the proximal face when in thedeployed orientation) through which the wire guides 306, 308 extend. Thecutout 340 is provided so that a pushrod carrying a suture (notillustrated) can follow a path into the arm 310 which is more gentlycurved than if the cutout is not provided, and therefore the cutoutfacilitates use of the element 300 to pass a length of suture materialaround a blood vessel. Fingers 354, 356 are also optionally providedadjacent to structures in the element 300 on which a suture may snagduring deployment, such as attachment portion 350 and the proximal endof the wire guides 306, 308. The fingers 354, 356 provide a ramp todeflect the advancing suture away from the structure against which thesuture may snag, and therefore facilitate use of the element 300.

Turning now to FIG. 28, the element 300 preferably includes a distalmosttapered tip 334 in which the distal port 336 of the tube 324 is formed.The tip 334 optionally includes a blind bore 338 in its interior whichfacilitates assembly of the tip to the cannula 302. Also illustrated inFIG. 28 is the yoke 322 secured to the interior of the cannula 302 withthe stationary tube 324 extending over the yoke 322 and for which theyoke 322 is provided with a unique shape.

FIG. 29 illustrated the element 300 with the arm 310 in its retractedorientation resulting from the lower pullwires 316, 318 having beenpulled proximally. As illustrated in FIG. 29, the free distal ends ofthe wire guides 306, 308 are, when the arm 310 is in the retractedorientation, preferably within the hollow interior of the arm, so thatthe wire guides do not interfere with the arm passing through thefenestration 320 and into the interior of the cannula 302.

FIG. 30 illustrates a cross-sectional view of the element 300, taken atline 30—30 in FIG. 29. Beginning at the top of the figure, the upperpullwires 312, 314 are illustrated in the trough 330. The exemplarycross-sectional shape of the arm 310 (rectilinear) can be seen as wellas the generally rectilinear cross-sectional shape of the guide tube304. The yoke 322 includes a pair of arms 342, 344, which are secured tothe interior of the cannula 302. A U-shaped curved middle portion 346extends between the two yoke arms 342, 344, and is sized to receive thetube 324 therethrough. The lower pullwires 316, 318 extend around theyoke arms 342, 344, and the yoke 322 acts as a bearing surface for thepullwires to pull the arm 310 back into the cannula 302. Alsoillustrated in FIG. 30 is an exemplary tool 348 extending through thetube 324, e.g., an anesthesia needle. Optional opening 332 is alsoillustrated.

The operation of the embodiment illustrated in FIGS. 27-30 will now bedescribed with reference to the drawing figures. The element 300 isextended adjacent to a blood vessel of interest, as described above withreference to FIGS. 126. Optionally, anesthesia can be administered usinga needle, e.g., needle 348. Once in position, the upper pullwires 312,314 are pulled proximally, which rotates the arm 310 out of the cannula302 and into the deployed orientation. Thereafter, a pushrod or thelike, carrying a length of suture material 154, is advanced distallythrough the tube 304, between the wire guides 306, 308, laterally intothe interior of the arm 310 and still between the wire guides 306, 308,and out of the arm 310. The suture is then snared by a snaring elementsuch as those previously described, and pulled proximally, thus loopingthe length of suture material around the blood vessel of interest. Thelower pullwires 316, 318 can be pulled proximally to rotate the arm 310back into the cannula 302 when desired.

While the invention has been described in detail with reference topreferred embodiments thereof, it will be apparent to one skilled in theart that various changes can be made, and equivalents employed, withoutdeparting from the scope of the invention.

What is claimed is:
 1. A ligation device comprising: a cannula having aproximal end, a distal end, and at least two lumens extendinglongitudinally from said proximal end to said distal end; a firstextendable member slidably received in said first cannula lumen, saidfirst extendable member having a distal end and being movable in saidfirst lumen from a retracted position in which said first extendablemember distal end is proximal said cannula distal end, and an extendedposition in which said first extendable member distal end is distal ofsaid cannula distal end, said first extendable member including adetachable element at said first extendable member distal end; a secondextendable member slidably received in said second cannula lumen, saidsecond extendable member having a distal end and being movable in saidsecond lumen from a retracted position in which said second extendablemember distal end is proximal said cannula distal end, and an extendedposition in which said second extendable member distal end is distal ofsaid cannula distal end, said second extendable member including a snareat said the distal end of the second extendable member distal end; atleast one of said the first extendable member and said second extendablemember including a portion which extends laterally across said cannulawhen said at least one of said first extendable member and said secondextendable member is in said extended position; and a vessel detectorlocated on the distal end of the cannula.
 2. A ligation device accordingto claim 1, wherein said detachable element comprises a ball, and saidsnare comprises a lateral opening in a distal portion of secondextendable member sized and positioned to receive and ensnare said ballin the lateral opening.
 3. A ligation device according to claim 1,further comprising a length of ligation material extending from thesecond extendable member to the first extendable member and beingsecured to said detachable element.
 4. A ligation device according toclaim 1, further comprising a length of ligation material extendingthrough said first extendable member and secured to said detachableelement.
 5. A ligation device according to claim 1, further comprising aDoppler wand in said cannula.
 6. A ligation device according to claim 5,wherein said Doppler wand is removably mounted in said device.
 7. Aligation device according to claim 5, wherein said Doppler wand ismounted in said device so as not to be removable.
 8. A ligation deviceaccording to claim 5, wherein said Doppler wand, said first extendablemember, and said second extendable member are coplanar.
 9. A ligationdevice according to claim 5, wherein said Doppler wand has a distal endproximal of said cannula distal end.
 10. A ligation device according toclaim 5, wherein said Doppler wand has a distal end distal of saidcannula distal end.
 11. A ligation device according to claim 7, whereinsaid cannula comprises a second lumen, said Doppler wand beingpositioned in said cannula second lumen.
 12. A ligation device accordingto claim 1, wherein said detachable element comprises a loop, andwherein said snare comprises a slot sized to receive portions of saidloop therein.
 13. A ligation device according to claim 1, wherein saidfirst extendable member curved portions are formed of a superelasticmaterial.
 14. A ligation device according to claim 13, wherein saidsuperelastic material comprises nitinol.
 15. A ligation device accordingto claim 1, further comprising a handle attached to said cannulaproximal end.
 16. A ligation device according to claim 15, wherein saidhandle comprises: a housing; a first actuation member slidably mountedin said housing, said first actuation member attached to said firstextendable member; and a second actuation member slidably mounted insaid housing, said second actuation member attached to said secondextendable member.
 17. A ligation device according to claim 16, whereineach of said first and second actuation members include first portionsextending outside said housing which allow a practitioner to manipulatethe first and second actuation members.
 18. A ligation device accordingto claim 16, wherein said housing comprises two longitudinally extendingslots, and each of said first and second actuation members include tabsextending through said slots to limit the range of motion of said firstand second actuation members.
 19. A ligation device according to claim1, further comprising a loop, wherein the first extendable membercomprises a slot at the distal end of said first extendable member, andsaid loop is releasably mounted in said slot.
 20. A ligation deviceaccording to claim 1, further comprising: a first block, a proximalportion of said first extendable member fixedly mounted to said firstblock; and a second block, a proximal portion of said second extendablemember fixedly mounted to said second block.
 21. A ligation deviceaccording to claim 20, wherein said first and second blocks areconnected together.
 22. A ligation device according to claim 20, whereinsaid first and second blocks are both cylindrically shaped.
 23. Aligation device according to claim 20, wherein each of said first andsecond blocks includes an interior chamber and a slot communicating saidinterior chamber with the exterior of said block.
 24. A ligation deviceaccording to claim 23, wherein said first and second extendable membersinclude proximal portions extending through said slots of said first andsecond blocks, respectively.
 25. A ligation device according to claim 1,wherein both of said first and second extendable members include curvedportions.
 26. A ligation device according to claim 1, wherein saiddetachable element comprises an arrowhead-shaped member, and said snarecomprises a lateral opening in a distal portion of said secondextendable member sized and positioned to receive and ensnare saidarrowhead-shaped member in the lateral opening.
 27. A ligation deviceaccording to claim 26, wherein said first extendable member and saidsecond extendable member both include exterior surfaces havingelectrical insulation thereon.
 28. A ligation device according to claim1, wherein said first extendable member and said second extendablemember both include closed distal ends and laterally inwardly directedopenings.
 29. A ligation device according to claim 28, wherein saidclosed distal ends of said first and second extendable members areconically shaped.
 30. A method of preparing an anatomical vessel forligation, comprising: providing a cannula including a first extendedmember, a second extended member, an ultrasonic vessel detector, and adistal end; positioning the cannula adjacent to an anatomical vessel;transmitting ultrasound signals toward the vessel with the ultrasonicvessel detector; receiving ultrasound signals reflected by the vesselwith the ultrasonic vessel detector; positioning the first extendedmember on a first side of the vessel; positioning the second extendedmember on a second side of the vessel opposite the first side; andextending a length of ligation material between the first and secondextended members on a side of the vessel opposite the cannula distalend.
 31. A method of preparing an anatomical vessel for ligation,comprising the steps of: positioning a cannula adjacent to said vessel,said cannula including a first extendable member, a second extendablemember, a Doppler wand, and a distal end; transmitting ultrasoundsignals toward said vessel with said Doppler wand; receiving ultrasoundsignals reflected by said vessel with said Doppler wand; extending saidfirst extendable member on a first side of said vessel; extending saidsecond extendable member on a second side of said vessel opposite saidfirst side; and extending a length of ligation material between saidfirst and second extendable members on a side of said vessel oppositesaid cannula distal end.
 32. A method according to claim 31, whereinsaid first extendable member includes a detachable element to which saidligation material is attached, and further comprising grabbing saiddetachable element with portions of said second extendable member.
 33. Amethod according to claim 32, further comprising the steps of:retracting said second extendable member in a proximal direction; andreleasing said detachable element from said first extendable member. 34.A device useful for guiding a length of ligation material around ananatomical feature comprising: a cannula including a hollow interior, adistal end, and a fenestration in the cannula proximal of the distalend; a hollow arm positioned in the cannula at the fenestration, thehollow arm including a rotatable pivot by which the arm is mounted tothe cannula, the arm being rotatable from a retracted orientation withthe arm positioned inside the cannula and a deployed orientation with aportion of the arm rotated about the pivot and through the fenestration;a pair of flexible and flat wire guides connected to the cannula andextending distally into the arm; at least one wire connected to the armand extending proximally; wherein when the at least one wire is pulledproximally, the arm is rotated about the pivot into the deployedorientation.
 35. A device in accordance with claim 34, wherein said atleast one wire comprises: a first pullwire connected to the arm on afirst side of the arm and extending proximally; a second pullwireconnected to the arm on a second side of the arm opposite the first sideof the arm and extending proximally; and wherein when the secondpullwire is pulled proximally, the arm is rotated about the pivot intothe retracted orientation.
 36. A device in accordance with claim 35,further comprising a yoke mounted in the cannula, the second pullwirepassing around the yoke, the yoke acting as a bearing surface for thepullwire.
 37. A device in accordance with claim 36, wherein the yokecomprises: a pair of arms secured to the cannula; and a curved middleportion extending between the yoke arms.
 38. A device in accordance withclaim 36, wherein the yoke is positioned distally of the arm pivot. 39.A device in accordance with claim 34, wherein the cannula furthercomprises a wire port proximal of the fenestration and on the same sideof the cannula as the fenestration, the at least one wire extendingthrough the wire port.
 40. A device in accordance with claim 39, whereinthe cannula further comprises a trough in the exterior of the cannulaand extending between the wire port and the fenestration.
 41. A devicein accordance with claim 34, further comprising a guide tube mounted inthe cannula, the wire guides including proximal ends secured to theguide tube, the at least one wire extending between the guide tube andthe cannula.
 42. A device in accordance with claim 34, wherein the wireguides have distal ends which are not secured to the arm.
 43. A devicein accordance with claim 34, wherein the arm further comprises a cutoutportion, the wire guides extending through the cutout portion when thearm is in the deployed orientation.
 44. A ligation device comprising: acannula having a proximal end, a distal end, and first and secondcannula lumens extending longitudinally from the proximal end to thedistal end; a first extendable member slidably received in the firstcannula lumen having a distal end and a detachable element at the firstextendable member distal end; a second extendable member which isslidably received in the second cannula lumen, which has a distal end,which is movable in the lumen from a retracted position in which saidsecond extendable member distal end is proximal said cannula distal end,and an extended position in which said second extendable member distalend is distal of said cannula distal end, said second extendable memberincluding a snare at said distal end of the second extendable memberdistal end; and at least one of said the first extendable member andsaid second extendable member including a portion which extendslaterally across said cannula when said at least one of said firstextendable member and said second extendable member is in said extendedposition.
 45. A ligation device for vessel occlusion, comprising: a. acannula having a proximal end, a distal end, at least one lumenextending longitudinally from the proximal end to the distal end; b. avessel detector at the distal end of the cannula; c. a first extendedmember having a distal end and a detachable element at the distal end ofthe first extended member; d. a second extended member having a distalend and a snare at the distal end of the second extended member; and e.at least one of the first extended member and the second extended memberhaving a portion which extends at least in part across the distal end ofthe cannula.
 46. The ligation device of claim 45 wherein the vesseldetector is an ultrasonic vessel detector.
 47. The ligation device ofclaim 46, wherein the ultrasonic vessel detector is removably mounted inthe device.
 48. The ligation device of claim 46, wherein the ultrasonicvessel detector is mounted in the device so as not to be removable. 49.The ligation device of claim 46, wherein the ultrasonic vessel detectorcomprises a Doppler ultrasound detector.
 50. The ligation device ofclaim 45, wherein a length of ligation material extends through at leastone of the first extended member and the second extended member and issecured to the detachable element.
 51. The ligation device of claim 45,wherein the detachable element is a loop.
 52. The litigation device ofclaim 51 wherein the snare includes a slot sized to receive portions ofthe loop therein.
 53. The ligation device of claim 45, wherein theportion which extends at least in part across the distal end of thecannula is formed of a superelastic material.
 54. The ligation device ofclaim 53, wherein the superelastic material comprises nitinol.
 55. Theligation device of claim 45, wherein the cannula has a handle attachedto the proximal end of the cannula.
 56. The ligation device of claim 55,wherein the handle comprises: a housing; a first actuation member whichis slidably mounted in the housing and which is attached to the firstextended member; and a second actuation member which is slidably mountedin the housing, which is attached to the second extended member.
 57. Theligation device of claim 56, wherein each of the first and secondactuation members include projections which extend out of the housing tofacilitate manipulation of the actuation members.
 58. The ligationdevice of claim 45, further comprising: a first block, a proximalportion of the first extended member fixedly mounted to the first block;and a second block, a proximal portion of the second extended memberfixedly mounted to the second block.
 59. A ligation device for vesselocclusion according to claim 58, wherein the first and second blocks areconnected together.
 60. A ligation device for vessel occlusion accordingto claim 58, wherein the first and second blocks are both cylindricallyshaped.
 61. A ligation device for vessel occlusion according to claim58, wherein each of the first and second blocks includes an interiorchamber and a slot communicating the interior chamber with the exteriorof the block.
 62. A ligation device for vessel occlusion according toclaim 45, wherein the snare comprises a lateral opening in a distalportion of the second extended member sized and positioned to receiveand ensnare the detachable element in the lateral opening.
 63. Aligation device for vessel occlusion according to claim 62, wherein thedetachable element comprises an arrowhead.
 64. A ligation device forvessel occlusion according to claim 62, wherein the detachable elementcomprises a ball.
 65. A ligation device for vessel occlusion accordingto claim 45, wherein the first extended member and the second extendedmember both include closed distal ends and laterally inwardly directedopenings.
 66. A ligation device for vessel occlusion according to claim65, wherein the closed distal ends of the first and second extendedmembers are conically shaped.
 67. A ligation device comprising: acannula having a proximal end, a distal end, and at least two lumensextending longitudinally from said proximal end to said distal end; afirst extendable means slidably received in said first cannula lumen,said first extendable means having a distal end and being movable insaid first lumen from a retracted position in which said firstextendable means distal end is proximal said cannula distal end, and anextended position in which said first extendable means distal end isdistal of said cannula distal end, said first extendable means includinga detachable element at said first extendable means distal end; a secondextendable means slidably received in said second cannula lumen, saidsecond extendable means having a distal end and being movable in saidsecond lumen from a retracted position in which said second extendablemember distal end is proximal said cannula distal end, and an extendedposition in which said second extendable means distal end is distal ofsaid cannula distal end, said second extendable means including a snareat said the distal end of the second extendable means distal end; atleast one of said the first extendable means and said second extendablemeans including a portion which extends laterally across said cannulawhen said at least one of said first extendable means and said secondextendable means is in said extended position; and a vessel detectingmeans located on the distal end of the cannula.